Mass storage is becoming a much more interesting tool than it has in the past for a larger number of applications because of the introduction of relatively new mass storage media such as optical disks. However, it is still necessary to find efficient ways of putting the data into mass storage and retrieving it.
Certainly the most efficient technique for inputting the contents of typed or printed documentation is with the use of optical scanning techniques. Methods and apparatus for handling incoming mail and the like in large quantities are disclosed in my copending application Ser. No. 536,769. In that application, the technique is used of optically scanning each document, identifying by data processing techniques "search words" which can subsequently be used to retrieve the documents and then storing the documents in a mass store, either in image form or in a data processing code such as ASCII. By "image form" it is meant that a digitized representation of the image of the document is stored in a form which is sometimes referred to as "bit mapped". While image storage requires much more memory, it has the advantage of speed over converting everything into dp code, which necessarily requires human editing to assure accuracy of conversion, and also has the advantage of being able to reproduce a replica of the original on a display or with a suitable printer, including signatures, letterhead "logos" and other non-text or unconvertible features such as drawings or graphics.
Retrieval has always been regarded as a requirement which necessitated conversion into dp code of all or a significant part of each document. Even in the system disclosed in Ser. No. 536,769, some conversion is used in connection with search words and the like, and that system is regarded as representing a minimum of conversion, and probably the most efficient system for bridging the gap between hard copy (paper) and mass electronic or optical storage. It would, however, be advantageous for many circumstances if the speed of putting information from documents into digital storage could be further increased so that the time for putting a page of printed or typed material into digital form in mass storage could be, in essence, not significantly longer than the time required for the page to be physically scanned by an optical scanning device.